ELi5: How do they connect electricity pylons? How do they join the lines?


How do they connect lines between the pylons? especially in areas where they go over mountains covered in large forests? I live in Japan and they are up on mountains where there are no roads and just loads of trees. I think about it every time when I see them! How do they join them? Is it drones? How did they used to do it? Am I the only one who thinks about this? Thank you in advance.

In: 8


They build the pylons first. The wire is attached to the pylon by a porcelain insulator, so they install those too. But they don’t attach any wire, they just hang a free spinning pulley wheel on each insulator.

They use rope that spans from one pylon to the next, rope is easier to get from one pylon to the next, either by truck or by a helicopter. At the other pylon, they wind the rope and pull the cable from the first pylon to the next. Repeat for all pylons.

If they run out of cable, they anchor the end of the cable to the insulator on the last pylon and start with a new spool of cable. Then just join the ends with metal connectors.

Modern times they use a helicopter to fly a small, strong messenger wire between the pylons. They use the ropes to then pull progressively larger and stronger wires between the poles. By using helicopters, you can fly the materials and crew in saving hours of hiking to the site in remote locations.

Before helicopters were common or if they weren’t available, workers would hike the valley to run the first line, then repeat the same process. They would also be required to build pylons closer together or even down into the valley since the largest cables were not able to go the far distances common today.